Electric sympathetic or secondary clock for induction-currents.



PATENTED FEB. 12, 1907.

, llllllA/l M. FISCHER. ELECTRIC SYMPATHETIG OR SECONDARY CLOCK POE INDUCTION cURRE Ts APPLIOAT ION FILED JULY 24, 1901.

Ton r ll whom, it Wan/y concern-.-

nrrni) s'rA rns PATENT. orrion.

iviAnfrIN FISCHER, or ZURICH, SWVITZERLAND, ASSIGNOR TO AOTIEN- Be .it knownthat I, MARTIN FISCHER, a resident'arid citizen of Zurich, Republic of Switzerland, have invented a certain new and useful Improvement in Electric Sym- ;--p .i thctic or' Seeondarv Clocks for Induction- Currents, of which the following is a specification. i I

I This invention has relation to electrically.- op eratcd clocks, aiulmorc particularly to the receiving, instruments for the secondary clocks operated by electric impulses, the periodicaltransinission of which is controlled by a central or master clock.

: n my copending ap lication for patent,

, rfiled July 5, 1900, Serial o. 22,582, of which the present application is a division, I have shown and described a master-clock combined'with a currcntrgcncrator ot peculiar construction u hereby the contacts usually required either for taking off current or vfor opening and closing the s:- condar v clock-circuit. are dispensed with.

One ofithe great disadvantages inherent to the receiving instruments wherein the armature of the electromagnet is directly connected 'to the ratchet-wheel that operates the m inute -lh'and lies in the liability oi said ratchet-wheel having imparted thereto angularmovements of greater amplitude than coi'it'emplat'ed, by the rapid.movements of the armature, and although means are provide'd' for liniitin'g'the throw ol the pawls in the direction of rotation of the ratclPet-wheel, or, in other words, to limit the positive movementsfot the pawlsf vet these have been found unreliable, re:-.ulting in irregularities hithe movements of the hands. ()n the other hand; the {sudden angular movement i1n parted to the ratchet-wheel on the minuteh and, arbor and the correspeinlmg sudden moveinent'ol the minute-haml l'requently causes the latter to tebound before the ratcl iet-wheelv is stopped or when suddenly stopped. These disadvantages become the inore pronounced when the electromagiwt energized by very short yet quite powerful imhlction-currents, such as generated by the 1nagneto-conductor described in my copending application, thedu'ation of said currents being but one-tenth the duration of batterycurrents of equal strength.

My invention has for its object the provision of means whereby. the disadvantages Specification of Letters Patent.

Application filed July 24, 1901. Serial No. 69,607.

G-EsELLso AnT MAGNETA, OF ZURICH, SWITZERLAND .ntcuac SYMPAT'HETIC 0R SECONDARY CLOCK FOR INDUCTION-CURRENTS.

Patented Feb. 12, 1907.

is to tGDIPOIZIlllY store the sudden energy of,

the moving armature and apply it gradually and resiliently to the actuating-pawl,- which latter thus moves at a different rate of speed from the armature and advances the ratchetwheel with which it engages with accuracy and precision.

Reference is made to the accompanying one sheet of drawings, in which Figure 1 is a side elevation of the actuating mechanism of a secondary clock, part of the permanent magnet being broken off Fig. 2, a top plan view of the same with parts broken away, and Fig. 3 a vertical section of Fig. 1- through the pole-pieces of the electromagnetarinatures.

In Fig. I. the numerals 13 and 14 indicate the two soft-iron cores of an electromagnet secured at one end to astandard 10, of magnetic material, the opposite endspf said cores projecting some distance from the bobbins of their eoilconductors 1] and 12 andbeing conneeted by a bridge 15 of non-magnetic material. 'lhe bridge 15 and standard 10 are provided with. bearings lor the ends oi a spindle H5, parallel with the axis of and between the bobbins oi the electronlagnet, said spindle carrying atits outerend andin theiield of force of the cores l3 and 14 a disk or sleeve 17, of non-magnetic material, to which are secured two thin soft-iron plates 18 and-19,which constitute the armature oi the electromagnet,

'said plates having theirouter ends bent to fit magnetieiicld ol" a permanent magnet D, siipported in anr suitable manner, the purpose of the latter being to polarize the arniatures 18'and10. I v

i The p awl-carrier or rock-shaft 20 is mountcd to oscillate in bearings formed in a standard. 20 and in the bridge 15,-and said shaft carries two elastic or flexible pawls 21 and 21, which act alternately as feed and retaining pawls, according to the direction of move ment of the rock-shaft, for the ratchet-wheel secured to the minute-hand arbor 6 of the lating member which carries the pawls and the electromagnet-armature and may conveniently take the form of a coil-spring 25, surroundin the shaft with one end engaged by the cran -arm 24 and the other by the aforesaid'pin 26 on the. armature, so that movement of thearmature will be imparted directly to the pawls through the coils of the spring and the rockashaft.

The eration is as follows, it being presumed tat currents alternating in direction energize the electromagnet-coils.

Supposing ,the armature elements 18 and 19 and the actuating-pawls 21 and 21 to be in the positions relatively indicated in Figs. 2 and 3, the

N wing of the armature element 19 being in with the electromagnet-cores can be contact with electromagnet-core 13, and the S wing 29 of armature element 18 in contact with electromagnet-core 14, as shownin Fig, 3. If now the electromagnet-coils are energized by a current of such direction that core 13 will be an N pole and core 14 an'S ole, the wing 28 of armature element 18 wil be at.- tracted by core 13 and its wing 29 repulsed by core 14. Inversely, the wing 27 of armature element 19 will be repulsed by core 13 andits wing 30 attracted by core 14. This vibration places spring 25 under tension, and said spring imparts a partial rotary movement to spind e 20 in .such a direction as to cause pawl 21 to ride over one tooth of the ratchetwheel 22 While pawl 21 turns said ratchetwheel a distance of one tooth. These movements of the pawls being reversed at the next change of olarity' of the cores 13 and 14, pawl 21 wil then make its negative movement and pawl 21' its ositive movement, the spindle 20 being oscil ated in an opposite direction under the tension of spring 25. If desired, direct contact of the armature-wings revented by mounting a non-magnetic sieeve on each of said cores.

From What has been said it will readily be understood that at each reversal of the polarity of the electromagnet-cores and the movements of the armature the spring 25 is brought under tension through the medium of the pin 26 and ismaintained under tension.

in that the armature is held stationary until the next change of polarity, the spring acting on crank-arm 24 to oscillate the spindle 20, the stop-plates 7 preventing the pawls 21 21 imparting to the ratchet-wheel 22 an angular movement greater th contemplated. By using spring or resilient pawls to drive the armature the instantaneous or sudden action of the pawls on the ratchet-Wheel is further counteracted.

Having thus described my invention, what I.claim as new therein, and desire to secure by Letters Patent, is

1. The combination with the driving-wheel of an electric clock of a shaft, spring driving and retaining pawls on the shaft to operate the wheel, an electromagnet and its armature, and a spring secured at one end to the shaft and at the other end to the armature, whereby the armature is yi'eldingly connected to the shaft.

2. The combination with a driving-wheel of an electric clock of a shaft parallel with the plane of the wheel,-as ring driving and ret aining awl secured to t e shaft one on each side of t e center of the wheeland projecting from the shaft substantially normal to the wheel, an electromagnet, an oscillating armature therefor and a s ring connecting the armature and shaft, substantially as described.

3. A secondary electric clock, comprising an electromagnet and an armature therefor; in combination with a toothed Wheel, feed and retaining pawls engaging the same, a

rock-shaft to which said pawls are secured, a

crank on said shaft and a spring connecting a tweenthe armature and oscillating member and through which the latter is oscillated by said armature.

5. In electrically-operated clocks, a receiving instrument comprisin an electromagnet, a permanent magnet and a bipartite armature 18 19 in the field of force of said permanent magnet and of the cores of the electromagnet; in combination with a toothed wheel, two awls enga ing the same, a rock-shaft to whic 1 said paw s are secured, a crank on said shaft and a spring coiled on the latter and having its ends connected to said crank and to one of the parts of the aforesaid armature, for the purpose set forth.

6. The combination with a driving-wheel of an electriciclock of a shaft, spring driving and retaining pawls secured to the shaft at different points of its length and engaging the wheel, an electromagnet having rojecting poles, a forked armature actuate by the magnet the forks of which engage the poles and limit its movement and a coil-spring con necting the armature and shaft.

- MARTIN FISCHER. Witnesses: A. LIEBERKNECHT, E. J WEs'rERMANN. 

